Anomalous Coronal Neon Abundances in Quiescent Solar Active Regions

摘要: The systematic differences between the solar photospheric and coronal composition are generally thought to be related first ionization potential (FIP) of trace elements. While there ample data showing that this is a significant factor, growing body observational evidence simple, FIP-based formula not whole story for abundances. One most troubling problems models apparent abundance variation high-FIP (> 11 eV) elements with respect one another. We describe variations (high-FIP) neon relative oxygen, (low-FIP) iron magnesium, in active region observations made by Flat Crystal Spectrometer on Solar Maximum Mission. show that, even quiescent regions, Ne/O can vary inconsistently simple empirical FIP models: it shows values about factor 2 both above below "standard" value 0.15 obtained from energetic particle measurements long-duration events (Reames). McKenzie & Feldman have recently invoked photoionization O I EUV radiation explain low ratio. Photoionization long-lived bath soft X-rays chromospheric evaporation been suggested as being responsible anomalous behavior flares, but flare conditions should apply regions present study. A complex picture involving detailed dynamics, geometry, environment differentiation layer(s) may required understand its variability.